I disagree with Cafe in Menga, even though groups seem to stick to themselves once seated it is easy to meet chicks when they are walking around or on the dance floor, I went there with mixed group of gringos but a lot of the Colombian girls invited me over to their tables etc. or if it is busy they will just sit with you if there aren't any more tables. It seems like a good place to me, and you can meet chicks outside and when it is shutting down it turns into a party on the street and in the parking lot.
Another option is to one of those big beer pitcher things with the tap and they put them on the table so you aren't stuck with buying a bottle if you don't have to, I don't remember the cost of the beer but it wasn't much.
Another option is to one of those big beer pitcher things with the tap and they put them on the table so you aren't stuck with buying a bottle if you don't have to, I don't remember the cost of the beer but it wasn't much.